Cross-posted from The Guardian, 21 Aug 2016
Scientist Peter Wadham’s A Farewell to Ice proceeds methodically. Ice cores, tubes of compacted polar snow, record the last million years of atmospheric change, during which the Earth has oscillated between ice ages and warm periods. Now the pattern is breaking.
“Our planet has changed colour. Today, from space, the top of the world in the northern summer looks blue instead of white. We have created an ocean where there was once an ice sheet. It is Man’s first major achievement in reshaping the face of his planet,” Wadhams writes.
Polar ice is thinning and retreating with unprecedented speed. All our ingenuity cannot, at present, change that. Because ice only grows in winter but can melt year-round, its growth rate is limited, while melt rate is unlimited.
Ice is extraordinary stuff. A “puckered honeycomb” of oxygen and hydrogen atoms, it is highly mutable in different states because the length of the hydrogen bonds in its molecules varies. Ice exists near absolute zero, the lowest temperature theoretically possible. Recent research suggests it may have entirely covered the Earth three times, making “snowball Earths”. Ice coats space dust, giving stars their twinkle. Life may have originated in that shining dust, according to the astronomer Fred Hoyle. Polar ice functions as Earth’s air- and water-conditioning system, and our thermostat.
Wadhams outlines how CO2 emissions are smashing the system, spinning the thermostat to hot. Without the albedo effect of ice – by which it reflects solar radiation up to 10 times more effectively than open water – we have entered a negative feedback loop.
Wadhams puts this plainly. “There is no period in Earth’s history where the rate of rise of atmospheric CO2 is as great as it is today.” The asteroid that finished the dinosaurs blasted 4.5 gigatonnes of carbon into the atmosphere, “yet the CO2 rate rise [in the aftermath] was still an order of magnitude lower than the current rate”.
The ice he worries about most covers Arctic seabeds – permafrost from the last ice age. Losing this will release huge methane plumes. Methane is 23 times more effective in raising global temperature than is CO2. Wadhams and colleagues have modelled the consequences using different dates for methane release.
We act, decisively and immediately, or our grandchildren pay full price, with our children impotent to help them
A business-as-usual approach by humanity makes 2035 a plausible moment for the permafrost to melt and methane to escape. The worst floods, fires, droughts and storms we have seen will be as nothing to what Africa, Asia and the Americas experience in this scenario. Millions die. Low-lying areas are inundated. Survivors live in a patchy post-apocalypse. Europe’s current refugee crisis would be dwarfed.
We still have time for drastic action, despite long procrastination, A Farewell to Ice concludes. The fall of Margaret Thatcher was bad for the ice: she was a fan of Wadhams’s work, quoting him extensively in her efforts to set up a body to understand and mitigate the loss of sea ice. Subsequent prime ministers did little or worse than nothing, suppressing facts that lobbyists in business and industry (some of them former Thatcherite ministers like Lord Lawson and Peter Lilley) did not like.
Last year’s Paris agreement, when global leaders resolved to prevent a temperature rise of 2C (with an aspiration of 1.5C), gives Wadhams hope. He believes there is now a common will across the world to confront and avert the nightmare. Solutions include wind, wave, solar, tidal and nuclear energy (not the perilous water-cooled reactor type David Cameron wanted for Hinkley Point, which have a terrible record, but the “pebble bed” type, apparently) and, above all, direct air capture (DAC), which has yet to be invented.
You pump air through a system that removes the CO2 and “either liquefies it or turns it chemically into something useful”, Wadhams says. Salvation requires “a research programme on the scale of the Manhattan Project” and voluntary change by all: home insulation, no more SUVs or budget flights. We act, decisively and immediately, or our grandchildren pay full price, with our children impotent to help them, if you believe this book. I am afraid I do.